User talk:Polyade

Thanks

Hello, welcome on Wikipedia, and many thanks for correcting my blunder in the example on Laplace expansion. -- Jitse Niesen (talk) 02:49, 17 August 2006 (UTC)

Thanks for your welcome notice which has now turned the talk page from a red link into a blue one. From my undergrad math studies I remember one exercise whose purpose was to show that the so-called n × n "Telefonmatrix" (a matrix with entries $a_{ij}=n(i-1)+j$) has rank two for n>1. Your example is just the case n=3 (the usual telephone key-pad). It thus seems to be a popular example... --Polyade 21:08, 18 August 2006 (UTC)